Reed Sensors & Magnets | Introduction

Reed sensors when paired with permanent magnets present an ideal method of sensing and detecting movement, proximity, metal detection, and liquid level and flow measurement. Reed sensors open and close their reed switch contacts in the presence of a magnetic field. Typically a permanent magnet is the moving member in the magnetic system. This can be a piston, a float, a rotating disk, and much more. Check out our Magnetic Interaction animations which demonstrates how a reed sensor operates with a magnet used in various movements and positions, affecting the magnetic field array.
Reed sensors come in hundreds of different sizes and shapes to meet a multitude of different application requirements. Reed Sensors are available in contact forms A, B, C, D, & E with power ratings up to 100W. They do well in long operating life applications if switching relatively low voltages and currents with life expectancy up to 1 billion operations.
Standex-Meder specializes in customizing designs to specific customer needs for a wide range of applications. Please contact us to provide the optimal solution for your specific needs.

Adjustable Thread Mount Reed Sensor

Thread mount reed sensors are supplied in a cylindrically shaped housing with cable terminals and offer the convenience of quick sensing adjustment. Available in plastic, stainless steel and brass. They include many options such as rated power up to 100W, switching voltages up to 1,000 VDC, SPST-N.O., SPST-N.C. and SPDT changeover contact configurations and more. Additionally any standard series my be customized to your specific needs with regards to custom cable length, wire termination, marking, etc.

ATEX Approved Reed Sensor

ATEX approved reed sensors are tested to carry out switching functions in potentially explosive atmospheres such that they will not become an ignition point when subjected to short circuits or adjacent component failures. They must also switch to a defined state when subjected to overload conditions. Reed sensor products meeting these requirements are generally referred to as intrinsically safe.

Best Value Reed Sensor

Standex-Meder best value reed sensor products are manufactured with our unique, patented, and highly automated production process allowing us to produce very cost-effective/industrial grade switches with outstanding physical and electrical characteristics. They are then packaged as a surface mount sensor or screw fastened flange mount sensor with a rectangular housing and cable terminals.

Best value ultraminiature bare glass surface mount (SMD) MK23 Series Reed Sensor series used in On/Off control switch, proximity, motion, position detection with high voltage and Form C (SPDT Changeover) options. Supplied in tape and reel according to IEC 286/part 3. Axial, gull-wing, inverse gull-wing, J-lead or helix lead designs available. UL Approval

High Temperature Reed Sensor

High temperature reed sensor products typically have an expansive temperature range of-55°C to 150°C and has no negative effect on the reed sensor’s operating characteristics. They are ideal under harsh environmental conditions that typically exist in under-the-hood environments (automotive).

High Voltage Reed Sensor

High voltage reed sensor products are SPST switches used for switching high voltage applications in the medial and ATE markets. They are capable of switching up to 10,000 VDC and currents up to 3 Amps.

High voltage surface mount (SMD) MK30 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection. Supplied in tape and reel according to IEC 286/part 3. Gull-wing lead design. UL Approval

Best value ultraminiature bare glass surface mount (SMD) MK23 Series Reed Sensor series used in On/Off control switch, proximity, motion, position detection with high voltage and Form C (SPDT Changeover) options. Supplied in tape and reel according to IEC 286/part 3. Axial, gull-wing, inverse gull-wing, J-lead or helix lead designs available. UL Approval

Latching / Bistable (1 Form E) Reed Sensor

A latching reed sensor or bistable reed sensor has an internal reed switch(es) with (Form E) contacts that are magnetically biased and can exist in either the normally open (N.O.) or normally closed (N.C.) state which is controlled by reversing the magnetic field. A bistable reed sensor is used in applications calling for extremely small power requirements, particularly in battery powered devices.

Magnet in Housing

A sensor magnet in housing is a permanent magnet that is epoxy encapsulated in a plastic or metal housing that is either cylindrical panel mount or adjustable screw mount, rectangular screw mount, or other custom mounted housing. Our sensor magnet products are used to actuate various magnetic reed sensors, hall effect sensor, and magnetic reed switches. The magnet is typically mounted to the moving part while the sensor or switch is mounted to a fixed surface.

The M11/B6, B8, B10, B12 series sensor magnet in housing is sealed in a convenient, easy adjustable threaded brass housing. Pair this magnet with our MK11/B (M6, M8, M10 or M12) series reed sensor (sold separate) for a proximity sensing solution. The brass housing is structurally robust enabling it to withstand higher torque settings, and resist high temperatures, moisture, and compression. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M11/M8 series sensor magnet in housing is sealed in a convenient, easy adjustable threaded plastic housing. Pair this magnet with our MK11/M8 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M11/M5, M11/S8 series sensor magnet in housing is sealed in a convenient, easy adjustable threaded stainless steel housing. Pair this magnet with our MK11/M5 or MK11/S8 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M03 series sensor magnet in housing comes in a cylindrical housing. Pair this magnet with our MK03 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M02 series sensor magnet in housing has a convenient screw mount. Pair this magnet with our MK02 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M21P/1, M21P/2 series sensor magnet in housing has either horizontal (/1) or vertical (/2) slotted screw mount holes. Pair this magnet with our MK21P/MK21M series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M05 series sensor magnet in housing has a single screw mount slot for adjustment. Pair this magnet with our MK05 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M13 series sensor magnet in housing has slotted holes for adjustable screw mounting. Pair this magnet with our MK13 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M04 series sensor magnet in housing has adjustable slotted screw mount holes. Pair this magnet with our MK04 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

The M06 series sensor magnet in housing comes in 3 different surface mount (SMD) sizes. Pair this magnet with our MK06 series reed sensor (sold separate) for a proximity sensing solution. The sensor should be mounted on a fixed surface with the actuating sensor magnet on the moving surface.

Metal Detection Reed Sensor

Metal detection reed sensor products are a great alternative to inductive proximity sensors. Available in screw fastened flange mount and PCB through-hole (THT) designs, these ferromagnetic metal detection sensors are suitable for a wide range of applications including but not limited to: end travel sensing limit switches, position control, and security uses such as door and window control, opening recognition contact and metal fire protection doors. Choose from normally open (SPST-N.O.) or normally closed (SPST-N.C.) contact forms.

Miniature Reed Sensor

Our miniature reed sensor series with glass lengths ranging from 9-14mm are some of the industries most used switches. Advancements in reed switch contact materials and construction have led to the ability of these smaller reed switches to maintain their contact ratings as they've become smaller. Miniature reed sensors include attributes like close differential, high current, mercury, high performance and even SPDT single pole double throw changeover contacts. Miniature reed switches play an integral role in two of the most critical areas for miniaturization, electronic/semiconductor equipment testing market and medical devices. Additionally they are heavily used in test equipment, telecommunications, security, medical, automotive, appliances, industrial, and aerospace among other sectors.

Panel Mount Reed Sensor

Panel mount reed sensors are supplied in a cylindrically shaped housing with cable terminals. They include many options such as rated power up to 100W, switching voltages up to 1,000 VDC, SPST-N.O., SPST-N.C. and SPDT changeover contact configurations and more. Additionally any standard series my be customized to your specific needs with regards to custom cable length, wire termination, marking, etc.

Permanent Magnets

Permanent magnets have a consistent non-varying magnetic field that has a north and south pole associated with them. The magnets come in different materials – rare earth, Alnico and hard ferrite. They all come in different sizes and shapes and have different magnetic strengths. The rare earth are the strongest, Alnico are the most stable, and ferrite are the least expensive. The magnetic strength is generally measured in gauss or milliTesla.
A Reed Switch requires either a permanent magnet or magnetic field in order to activate the switch, thus it is commonly called a magnetic reed switch. Magnets have reversible and irreversible demagnetization specifications. Engineers should consider shock, vibration, strong external magnetic fields as well as high temperatures in their designs. All these factors influence the magnetic force and the long term stability in different ways.
Preferably the magnet is mounted on the moving part of the application. Professional tuning of magnet and reed switch pairing can improve the functionality of the whole sensor-magnet system.

Types of Magnets

We offer the following types of permanent magnets:

AlNiCo (Aluminum Nickel, Cobalt, Iron and Titanium)

SmCo (Samarium–Cobalt) & NdFeB (Neodymium) - rare earth

Hf - hard ferrite

These are some of our most widely used models, others available as required.

Magnets have reversible and irreversible demagnetization specifications. Be especially careful with shock, vibration, strong and close external magnetic fields as well as high temperatures. All these factors influence the magnetic force and the long term stability in different intensities. Preferably the magnet is mounted on the moving part of the application. Professional tuning of magnet and reed switch can improve the functionality of the whole sensor-magnet system.

Reed Sensor Design Kit

Reed Sensor Design Kit provides design engineers with quick and convenient access to sensor systems for evaluation purposes, taking the guess work out of the sensor design process. Standex-Meder proprietary 3-D magnetic mapping equipment was used to accurately map out the activation distances in mm for 5 different positions and movement configurations of each sensor, along with its corresponding magnet.

Screw Mount Reed Sensor

Screw fastened flange mount reed sensors come in a rectangular housing with cable terminals. They include many options such as rated power up to 100W, switching voltages up to 1,000 VDC, SPST-N.O., SPST-N.C. and SPDT changeover contact configurations and more. Additionally any standard series my be customized to your specific needs with regards to custom cable length, wire termination, marking, etc.

SPDT Changeover (1 Form C) Reed Sensor

Changeover reed sensor products contain one or more single-pole double throw SPDT reed switches where a normally closed contact opens before a normally open contact closes. A changeover reed sensor is also referred to as a (Form C) reed sensor or break-before-make (Form C) which defines the sequence in which one reed switch contact opens its connection to another contact and then closes its connection to a third contact. Changeover reed sensors can also be used as a (Form B), normally closed reed sensor (N.C.) application. Check out our Magnet Interaction page to see animated examples of how reed switches are used in a sensing environment.

SPDT Changeover surface mount (SMD) MK01 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection with high power switch option. Supplied in tape and reel according to IEC 286/part 3. UL Approval

Best value ultraminiature bare glass surface mount (SMD) MK23 Series Reed Sensor series used in On/Off control switch, proximity, motion, position detection with high voltage and Form C (SPDT Changeover) options. Supplied in tape and reel according to IEC 286/part 3. Axial, gull-wing, inverse gull-wing, J-lead or helix lead designs available. UL Approval

SPST-N.C. (1 Form B) Reed Sensor

A normally closed (SPST-N.C.) or Form B reed sensor represent the state of contacts before any magnetic field is applied to them in which they exist in the closed state. To open the contacts a magnet of opposite polarity is brought into the existing magnetic field cancelling the field from the existing permanent magnet. This in turn opens the contacts. The magnet must be carefully chosen so that its strength is strong enough to cancel the field from the permanent magnet, but not too strong that it overpowers the permanent magnets field, which could re-close the contacts. Furthermore, care must be taken in selecting the physical operate and release points. Knowing where these 3 magnetic lobes are is essential for proper sensor operation. Check out these animated Magnet Interaction examples showing the reed switches in their sensing environment.

SPDT Changeover surface mount (SMD) MK01 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection with high power switch option. Supplied in tape and reel according to IEC 286/part 3. UL Approval

SPST-N.O. (1 Form A) Reed Sensor

SPST-N.O. (1 Form A) Reed Sensor products contain a single internal reed switch that is a single pole single throw type switch with it's contacts in the normally open (Form A) position, drawing no power. A permanent magnet or magnet in housing is brought into the sphere of influence of the reed switch closing the contacts and carrying out the sensing application.

High voltage surface mount (SMD) MK30 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection. Supplied in tape and reel according to IEC 286/part 3. Gull-wing lead design. UL Approval

SPDT Changeover surface mount (SMD) MK01 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection with high power switch option. Supplied in tape and reel according to IEC 286/part 3. UL Approval

Best value ultraminiature bare glass surface mount (SMD) MK23 Series Reed Sensor series used in On/Off control switch, proximity, motion, position detection with high voltage and Form C (SPDT Changeover) options. Supplied in tape and reel according to IEC 286/part 3. Axial, gull-wing, inverse gull-wing, J-lead or helix lead designs available. UL Approval

Surface Mount (SMD) Reed Sensor

Surface mount reed sensor products are an SMT design used in switching and sensing applications. Choose from bare glass or rugged thermoset overmolded versions in SPST-NO, SPST-NC or SPDT changeover contacts. Choose from 9 different switch models from 7mm and up, ranging from 0-100W and switch voltages up to 1,000 VDC as well as 5 different surface mount lead designs. They are typically supplied in tape and reel and are ideal for automatic pick and place.

High voltage surface mount (SMD) MK30 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection. Supplied in tape and reel according to IEC 286/part 3. Gull-wing lead design. UL Approval

SPDT Changeover surface mount (SMD) MK01 Series Reed Sensor used in On/Off control switch, proximity, motion, position detection with high power switch option. Supplied in tape and reel according to IEC 286/part 3. UL Approval

Best value ultraminiature bare glass surface mount (SMD) MK23 Series Reed Sensor series used in On/Off control switch, proximity, motion, position detection with high voltage and Form C (SPDT Changeover) options. Supplied in tape and reel according to IEC 286/part 3. Axial, gull-wing, inverse gull-wing, J-lead or helix lead designs available. UL Approval

Ultraminiature Reed Sensor

Ultraminiature reed sensor series range in body length from 8mm and below and are some of the smallest sensors currently available in the world. The MK24 series surface mount reed sensors are the smallest in the industry offered in a normally closed contact form.

Best value ultraminiature bare glass surface mount (SMD) MK23 Series Reed Sensor series used in On/Off control switch, proximity, motion, position detection with high voltage and Form C (SPDT Changeover) options. Supplied in tape and reel according to IEC 286/part 3. Axial, gull-wing, inverse gull-wing, J-lead or helix lead designs available. UL Approval